<template>
  <div class="spec-preview">
    <img :src="skuInfo.skuDefaultImg" />
    <div class="event" @mousemove='playImg'></div>
    <div class="big">
      <img :src="skuInfo.skuDefaultImg" :style="{left:-(left*2)+'px',top:-(top*2)+'px'}" />
    </div>
    <div class="mask" :style="{left:left+'px',top:top+'px'}"></div>
  </div>
</template>

<script>
import { mapGetters } from 'vuex';
import _ from 'lodash';
export default {
  name: 'Zoom',
  data() {
    return {
      left: 0,
      top: 0
    };
  },
  computed: {
    ...mapGetters('detail', ['skuInfo']) // skuDefaultImg
  },
  methods: {
    // playImg(e) {
    //   console.log(e.offsetX, e.offsetY);
    //   let x = e.offsetX - 100;
    //   x < 0 ? (x = 0) : x;
    //   x > 200 ? (x = 200) : x;
    //   let y = e.offsetY - 100;
    //   y < 0 ? (y = 0) : y;
    //   y > 200 ? (y = 200) : y;
    //   this.left = x;
    //   this.top = y;
    // }
    
    // throttle 节流
    playImg: _.throttle(function (e) {
      // console.log(e.offsetX, e.offsetY);
      let x = e.offsetX - 100;
      x < 0 ? (x = 0) : x;
      x > 200 ? (x = 200) : x;
      let y = e.offsetY - 100;
      y < 0 ? (y = 0) : y;
      y > 200 ? (y = 200) : y;
      this.left = x;
      this.top = y;
    }, 1000 / 60)
  }
};
</script>

<style lang="less">
.spec-preview {
  position: relative;
  width: 400px;
  height: 400px;
  border: 1px solid #ccc;

  img {
    width: 100%;
    height: 100%;
  }

  .event {
    width: 100%;
    height: 100%;
    position: absolute;
    top: 0;
    left: 0;
    z-index: 998;
  }

  .mask {
    width: 50%;
    height: 50%;
    background-color: rgba(0, 255, 0, 0.3);
    position: absolute;
    left: 0;
    top: 0;
    display: none;
  }

  .big {
    width: 100%;
    height: 100%;
    position: absolute;
    top: -1px;
    left: 100%;
    border: 1px solid #aaa;
    overflow: hidden;
    z-index: 998;
    display: none;
    background: white;

    img {
      width: 200%;
      max-width: 200%;
      height: 200%;
      position: absolute;
      left: 0;
      top: 0;
    }
  }

  .event:hover ~ .mask,
  .event:hover ~ .big {
    display: block;
  }
}
</style>